i-ramen.net is an amazingly meticulous web site that chronicles one man's daily consumption of different kinds of instant noodles since 1997. It appears from the way they're numbered that he is now on his 4,308th bowl. For each new type of instant noodle, he creates a thorough chart that includes a full ingredients list; comments on texture, flavor, quantity, and price; and a starred rating.
The first question that popped into my head while browsing his site was: I wonder how his health is! And the second: How many flavors of instant ramen can there possibly be? Looking back at his archives, though, I see that at the end of 1998, just over a year after starting this instant noodle journey, he had reached 227 flavors of ramen. His more recent reviews include flavors from Korea, Thailand, India, and beyond. Given his international reach and commitment to ramen, I suppose 4,000+ may be entirely possible. (I didn't read every single review, so I can't say for sure whether there are duplicates.)
The site is in Japanese, but he also makes YouTube videos of his more recent exploits, which you can see here.
(Thanks, Vijay Karunamurthy!)